This invention relates to thrust bearings subjected to reversing loads as are present in slant axis rotary mechanisms used as engines, pumps, compressors, etc. More specifically, the invention relates to an improved means for lubricating thrust collars and bearings.
In typical thrust bearing structures employed in prior art slant axis rotary mechanisms, it is difficult to develop an oil film to insure adequate lubrication by reason of the typical utilization of flat elements resulting in a flat interface between a thrust collar and a thrust bearing. In general, some nonparallelism of the sliding components is required to develop a hydrodynamic oil film wtih load carrying capacity provided by converging portions of the oil film. Alternately, in bearings operating on the "squeeze film" principle, when the load reverses, it is supported readily because a finite time is required to squeeze oil out of the bearing through the rather narrow clearances employed. However, the load must not persist sufficiently long as to allow the film to be totally squeezed out of the bearing permitting metal-to-metal contact to occur. And, just as it takes a finite time to squeeze oil out of the bearings, a finite time is required to replenish the interface with oil so that another load cycle can safely take place with adequate lubrication.